Improve RAG vector classified docs scenario

scenarios/06-rag-vector-classified-docs/sql/99_reset.sql

@@ -20,6 +20,8 @@ BEGIN EXECUTE IMMEDIATE 'DROP DATA ROLE rag_exec_role'; EXCEPTION WHEN OTHERS TH
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 BEGIN EXECUTE IMMEDIATE 'DROP ROLE rag_session_role'; EXCEPTION WHEN OTHERS THEN NULL; END;
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+BEGIN EXECUTE IMMEDIATE 'DROP ROLE rag_legacy_retrieval_role'; EXCEPTION WHEN OTHERS THEN NULL; END;
+/
 BEGIN EXECUTE IMMEDIATE 'DROP END USER nina'; EXCEPTION WHEN OTHERS THEN NULL; END;
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 BEGIN EXECUTE IMMEDIATE 'DROP END USER heitor'; EXCEPTION WHEN OTHERS THEN NULL; END;